Tack-fr ee alkaryl sulfonate



Patented Nov. 11,1952

TACK-FR EE ALKARYL SULFONATE DETERGENT Vincent J. Keenan, Ardinore, Pa.,assignor to The Atlantic Refining Company, Philadelphia, Pa.. acorporation of Pennsylvania N Drawing.

Application June 17, 1950,

Serial No. 168,833

12 Claims. (Cl. 252-461) This invention relates to a detergent composition containing a water-soluble alkyl substituted aryl sulfonate, andmore particularly to a composition containing a Water-soluble alkyl-sub-V stituted aryl sulfonate which does not develop objectionable tacky,adhesive sensations when used in contact with the human skin.

Detergent compositions in the form of bars, creams, shampoos, andsimilar cosmetic products have been made heretofore in whichwatersoluble alkyl-substituted aryl sulfonates constituted the surfaceactive agent. Since these sulfonates, which hereinafter will be termedalkyl aryl sulfonates, do not form insoluble compounds with the calciumor magnesium ions found in hard 'water, it was assumed that suchcompositions would prove especially'valuable in hard water areas wherepresent fatty acid soap compositions precipitate insoluble soaps andexhibit poor detergent and lather properties. Cosmetic preparationscontaining an alkyl aryl sulfonate were found, however, to produce an adhesive or tacky sensation on the skin. This propertyis objectionable, somuch so, that in spite of the superior detergency, lather, andsolubility properties of alkyl aryl sulfonate compositions as'comparedwith fatty acid soap compositions in hard water, the sulfonatecompositions have gofdmet with public acceptance in the cosmetic e v rThe exact reason for the development of this tackiness by alkyl arylsulfonate-containing compositions has not been exactly determined.However, the alkyl aryl sulfonates are highly active surface-activeagents and consequently, it ispossible that they remove most of thenatural protective oils of the skin, with the result their stronglypolar sulfonate radicals become attached to or at least closelyassociated with the proteins of the skin, and thereby produce thecharacteristic, highly objectionable tacky sensation. Whatever thetheoretical explanation, this tack has prevented full commercialutilization of alkyl aryl sulfonates in cosmetic detergents and untilthe present invention, no solution had been found to this problem.

{ In addition, alkyl aryl sulfonate formulations are ,extremelydifficultto extrude into bar forms.

These formulations are much too hard and either "freeze in the extruderor discharge as lumps likeribbon. H a

i It is an object otthis invention to produce a detergent composition inthe form of a solid bar, cream, or liquid which contains an alkyl arylsulfonate as surface active agent, and which,

instead of in the form of a smooth, coherent, gelwhnused in contact.with thehuman skin, does not develop objectionable tacky sensations.

It is an additional object to provide a deter gentcomposition containingan "alkyl substituted aryl sulfonate which may be-easily and smoothlyextruded into coherent gel-like ribbons for the production of bars.

The detergent compositions of the present in vention may be prepared byforming a primary aqueous dispersion of the alkylaryl sulfonate togetherwith commercial lecithin in an amount of at least 20%, but less than 70%by weight, based on the weight of the dry sulfonate. The amount of waterused to form the primary dispersion is not critical, but in generalmayrange, for example, between 0.5and 5 volumes of-water per volume of dryingredients, this range being preferred in order to form a fluiddispersion which does not contain a large excess of water, since thewater must be removed by a subsequent drying operation. In order toimprove the appearance or performance of the finished product, variousagents such as fillers, abrasives, dyes, perfumes, emollient oils,glycerol, and waxes may be dispersed in the primary mixture to form afinal dispersion which when drum or spray dried, will produce a productin the form of freelyflowing flakes, sheets, pellets, or-beads. Inaddition, such dried material may be molded'into smooth bars or ploddedor milled and subsequently extruded, sliced, and molded into bars. Thecompositions produced as above described, in addition to their ease ofextrusion to form bars.-

, are entirely free of the objection of causing a tacky sensation whenu'sed in contact with the hydrogen atoms of the aromatic.

human skin, a It is known that in many cases, fatty acid soap productscause severe dermatic and allergic reactions due to the'fact that theyhydrolyze in water togive an alkaline solution.- 'Ihecompositions of thepresent invention, however, en-' tirely avoid such objectionablereactions since: both the lecithin and alkyl aryl sulfonatesar'e:

v non-alkaline even in aqueous solutions.

The water-soluble alkyl aryl sulfonates' suit--; able for use in thepresent detergent composi-: tions are prepared by sulfonating a suitablealkyl aromatic and neutrallizing' the resultant alkylaryl. sulfonic acidwith an alkaline compound.

The alkyl aromatics suitable for preparing the desired sulfonates'havean alkyl group containing from 8 to 15 carbon atoms. In addition tothelong chain alkyl group, short chainalkyh groups may maybe substitutedfor other nuclear Th oin-J pounds maybe prepared by a variety ofmethods, for example, by the alkylation of an aromatic hydrocarbon withalbranched-chain olefin -hav-j ing from 8 'to 15 carbon atoms in thepresence similar acid-type catalysts. The olefins may be obtained fromthe polymerization of propylene over phosphoric ,acid or similarcatalyst or by the polymerization of butylenes, etc. The aromaticemployed may be benzene, naphthalene, toluene, any one of the isomericxylenes or mixtures of such isomers, ethyl benzene, propyl benzene, orsimilar lower aIkyL-aromatics.

Another method of preparation involves the reaction of an alcoholcontaining from 8 to 15 carbon atoms with an aromatichydrocarbon in thepresence of such catalysts as H2SO4,:BF3, BF3H2SO4, BF3-H3PO4, or AlCla.The ,alcohols may be obtained by the reaction of aniolefin with carbonmonoxide and hydrogen in the socalled x0 process, or by the oxidation.;of paraffinic hydrocarbons. The aromatic hydrocarbon-email .b enzene,naphthalene, .toluene.

yl benz ne, nropyl .b nzene,.ors imi1a1' lower elkv -zaromaties.

Athird methodoi-prepa ationof ,the alkyl aromatics employs :achlorinated hydrocarbon havin g;f -rom r 8 to :carbon atoms reacted withthe {a matic hydrocarbon {in the presence .of a Miedel-Crafts catalystsuch as AlC13. .The 7 alkyl ha idemay be conveniently obtained bychlorinating-the z-proper petroleumiraction such as aizkerosenefraction. The-aromatics suitable in the previousmxamples arelikewisesuitablein this method.

Typical -compoundswhich fallwithin this class are-.nonyl benzene,dodecyl benzene, pentadecyl benzene,,nonyl-toluene, dodecyl toluene,pentadecyl toluene, dodecyl ,Xy1ene,-andthe like. Obviously,-,alargenumber of-simila-r-compounds might be .enumerated; however,.intheinterest of brevity eandnlarity, it.-is:sufficient to state that allcompounds having an aromatic .nucleus with one side-chain containingfrom 8 170 15 carbon atoms and-including-also those compoundswhereinetheraromatic nucleus has, in addition to the 8 -,to ;15 carbon,atom side-chain, one or more short chain .alk-yl radicals up to -3carbon atoms in:-length.

rflhe agentswhich may be employed in sulfonating the alkyl aromaticstoproduce-the alkyl aryl sulfonic acid include sulfuric 'acid ranging inconcentration from-about 98% to-100%,-fuming sulfuric acid containing'up to free S03, chlorosulfonic acid, and similar reagents.

The alkylaryl sulfonicacid resulting from thesulfonatlonsterrmay-beneutralized with a variety of ;:alkalinecompounds,forexample, with an alkali or alkaline earth metal hydroxide orcarbonate, with ,ammorula, or with various amines including primary;secondary, and tertiary alkyl amines, alkyl alkanol ,rami-nes, -alkanolamines, hetero cyclic amines; or other alkaline compoundswhich willproduce "watersoluble su'lfonates. Specific examples of the:aminesi-nclude methyl amine, dimethylamine, -trimethylami-ne,ethanolamine, diethanolamine, diethyl ethanolami-ne, ethyl-diethanolamine, itriethanolamine, pyridine, methyl pyridine,randrsimilar compounds.

The water-soluble alkyl aryl sulfonate soap resultinafrom theneutralization step may be used :inthe zfinal composition either aloneor in combination with various amounts of asimilar soap ,orysoapsprepared as above described.

=Thejlecithins whichwmay be used include'both the animal and vegetabletypes, all of which are structurally, esters of-glycerol and resemblea.fat, b ut-; difier .therefrom in that .at least one .f-atty acid,radiealis replaced by a complex amine-phos- 'Saponin The amine is aquaternary The phoric acid radical. ammonium compound known as choline.

,lecithins of the vegetable type are derived from :soy bean, corn,linseed, peanut, ,or other similar oils and are commercially availableas dispersions -or solutions in from 30% to 40% of the oils. The

term lecithin, as used herein and in the of thele-eithinand 35% of theoil. Soya lecithin is especiallyuseful from the standpoint ofavailability and low cost.

The amount of lecithin employed varies with qthejintended use of thefinal detergent. However, 'in'general, the amount ranges between 20% to7.0% "by .weight based on the dry sulfonate. Amounts less than 20%;'fail to impart detackifyinsnroperties to the finished detergent,whereas amou ts greater than 70% interfere with :the detergenteand.lethering properties of the finished product. .It :has been vfound, inv.tact, hat ithe addition ,oiilecitliin toaalkyl aryl :sulfonatecompositionsiails to improve detergentactiomlathering, or foamstabilityof-the: finished detergent. The only effect of the'lecithin, as hasbeenrstated, is to improve the :extrudability and eliminate tack.The-amountof sulfonate and'lecithin in the. finished detergentpreferablyranges between 5% and 65 %,-and 1%.to40%,,respectively. How'- ever, inall cases, including those'intermediate theabove limits, the amount ofthe lecithin by weight based upon the weight of :sulfonate must rangebetween 20% and 70%. The remainder of the composition mayconsistof'fillers, dyes, per- 1 fumes,.emol1ien-t -oils,-and waxes, all ofwhich-are inert with respect "to detergent action. Small amounts ofshort-chain sodium alkyl aryl sulfonates Such as sodium xylene;-sulfonate, sodium isopropyl sulfon-ate, sodium isopropenyl sulfonate,and the like, may ,beadded ,to the composition forthe purpose ofproducing 'rapidsudsing .of the finished detergent, but this refinementis not necessary or critical.

As 'hereinbefore stated, the instant compositionsare-suitablefor both:solidand liquid formulations. In the two-tables immediately-following,typical formulations are shown giving desirable percentages ofcomponents, on the basis of the weight of the finished composition for abar soap (Tablet) and a liquid soap (Table l1). These examples are not.totbeconstrueda's limiting-the invention, since, as is well known inthe artofsoapmanufacture, many-modifications may be made by theadditionof various inert materials, some of which have .been.enumeratedhereinbefore.

TABLE vI Bar soaps "Per cent Alkyl aryl sulfonate '15 to 50 Lecithin .3to '25 Starch 0 to 50 China clay 'O'to 35 Talc .,0 to 35 Xylenesulfonate 0 to 0 Polyethylene glycol waxes 0to'l0 (2000-6000 mol. wt.)Natural waxes '(carnau'ba, cande'llila, bees, etc.)

In all cases, the .amountof lecithin ranges between l2)0% and 70% of thealkyl aryl sulfonate on tlry weight asis.

Liquid soaps Per cent 1 The upper limit given is true only for alkylaryl sulfonates which are soluble to the extent, for example, thetriethanolamine sulfonates; other "sulfonates such as alkali metalsulfonates are soluble in water in an amount only up toabout 30% byweight, which obviously would define the upper limit in those cases.

I In the case of the liquid soaps, as in all others, the weight oflecithin ranges between 20% to 70% by weight of the sulfonate. Where thesulfonate is present in amounts near the upper range of concentration itmaybe impossible to have the lecithin present in amounts approaching 70%because of r'solubility limitations. Where, however, the amount ofsulfonate is somewhat removed from the upper range, the amount oflecithin may be increased accordingly. By way of example, a compositionmight contain 40% sulfonate, 28% lecithin, and 32% water. Compositionshaying amounts of sulfonate and lecithin near the upper limits of theabove stated ranges for liquid soaps, may actually be cream or gel-likein form suitable for shampoos, whereas compositions containing amountsof sulfonate and lecithin nearer the lower limits will be true TABLE III6 the weight of the dry salt cf'the alkylarylsulfonic acid. 1 p 2. Adetergent composition comprising a watersoluble salt of an alkyl arylsulfonic acid in which the alkyl radical contains from 8 to 15 carbonatomsand from to 70% of lecithin'by weight based on the weight of'thedry salt'of the alkyl aryl sulfonic acid. r

3. A detergent composition comprising the sodium salt of an alkyl arylsulfonic acid in which the alkyl radical contains from 8 to 15"carbon-atomsand from-20% to 70% of lecithin by Weight:

based on the weight of the dry salt. r

4. A detergent composition comprising the triethanol amine salt of analkyl aryl sulfonic acid in which the alkyl radical contains from 8 to15 carbon atoms, and from 20% to 70% of lecithin by weight based on theweight of the dry salt.

5. A detergent composition comprising the sodium salt of nonyl benzenesulfonic acid and from 20% to 70% of lecithin by weight based on theweight of the dry salt. U

6. A detergent composition comprising the sodium salt of dodecyl benzenesulfonic acid and from 20% to 70% of lecithin by weight based on theweight of the dry salt.

7. A detergent composition comprising the sodium salt of pentadecylbenzene sulfonic acid and from 20% to 70% of lecithin by weight based onthe weight of the dry salt.

8. A detergent composition comprising the magnesium salt of dodecylbenzene sulfonic acid and from 20% to 70% of lecithin by weight based onthe Weight of the dry salt.

9. A detergent composition comprising a watersoluble salt of an alkylaryl sulfonic acid in an amount ranging between 1 5% and 65% of thetotal weight of the detergent and lecithin in an amount ranging between20% and 70% by weight based on the weight of the dry salt of the alkylaryl sulfonic acid.

Composition (amounts in parts by Weight) Component sodium dodecylbenzene sulfona .4 100 100 150 100 50 25 130 sodium nonyl benzenesulionate 4. 75 magnesium dodecyl benzene sulfonate 150 75 25 triethanolamine salt of dodecyl benzene sulfonic acid soya lecithim; '50 70 50 5Ocorn lecithin i 40 linseed oil lecithin t 150 90 80 200 100 25 10 xylenesulionate 75 2O 5 25 20 polyethylene glycol wax (mol wt. about 6000) 3010 30 15 10 carnauba wax. in 5 beeswax 5 10 8 10 In all of the aboveexamples, the active deterr sulfonates, however, if desired, a'portionof the alkyl aryl sulfonate or sulfonates may be replaced with otherknown detergents such as alkyl sulfates, alkyl aryl sulfates, fatty acidsoapsand similar compounds.

I claim:

1. A detergent composition comprising a watersoluble salt of an alkylaryl sulfonic acid and 7 from 20% to 70% of lecithin by weight based on10. A detergent composition comprising a gent component of suchformulations is shown as water-soluble salt of an alkyl aryl s lf ni ian alkyl arylsulfonate or mixture of alkyl aryl in which the alkylradicalcontains from 8 to 15 carbon atoms, said salt of the sulfonicacid being present in an amount ranging between 15% and 65% of the totalweight of the detergent,

O and lecithin in an amount ranging between 20% carbon atoms, said saltbeing present in an amount ranging between 15% and 65% of the 1 totalweight of the detergent, and lecithin in an amountranging between 20%and 70% by weight based on the weight of the dry salt.

VINCENT J. KEENAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,232,117 Kyrides Feb. 18, 1941FOREIGN PATENTS Number Country Date 1 473,638 Great Britain Oct. 18,1937

1. A DETERGENT COMPOSITION COMPRISING A WATERSOLUBLE SALT OF AN ALKYLARYL SULFONIC ACID AND FROM 20% TO 70% OF LECITHIN BY WEIGHT BASED ONTHE WEIGHT OF THE DRY SALT OF THE ALKYL ARYL SULFONIC ACID.